To anyone wondering what this is about:
The computer in question is a Dell Inspiron 9100 that someone set a password on, then promptly forgot it.

Well, lets see...

There are 3 possible passwords that can be set:

1. Windows user. If the machine displays the windows logo, before prompting, this is what has been set. This may be fixed by booting it into 'Safe Mode' (press F5 when windows begins booting) I believe there are enough guides about what needs to be done after that, already on the net.
(Google it)

2. PC Boot password. It may have had a password set in the BIOS to prevent someone from booting the computer. This can usually be cleared by unplugging the BIOS backup battery.
See page 119 of the user manual for that.
http://support.euro.dell.com/support/ed ... 806a02.pdf

3. HDD-password. This is the biggest baddie. If this password has been set, you will need either that password, or a 'master password' to clear it. If this has been set, you will need to call the DELL support hotline and pray that the HDD had one set before it left DELL. They will need the make, model and serial number of the HDD, though. This may or may not be displayed after you've tried to input the incorrect password too many times.

If it was the HDD-password, and DELL can't help you, you will have to contact a firm specialising in data recovery, like IBAS, but the cost is likely to be rather high. (They often start at €400 just for evaluating the case) If the data on the HDD isn't worth the amount, then it may be easier to just bin it and get a new one...